The Dix-Hallpike tests for benign paroxysmal positional vertigo (BPPV). A test is positive when a patient reports vertigo, dizziness, or sensation of movement or falling with nystagmus present. When the head is in this position, it allows the posterior canal to be aligned with the gravitational vector, which causes movement of otoconial debris through the posterior canal. Otoconia within the long-arm of the posterior canal cause excitation (ampullofugal direction of endolymph) and lead to nystagmus generation (upbeat and ipsitorsional). Otoconia within the short-arm of the posterior canal cause inhibition (ampullopetal direction of endolymph) and lead to nystagmus generation (downbeat and contratorsional). It is critical that the testing position is held for a minimum of 30 seconds, as this allows for latency, the time needed for the otoconia to move and deflect the cupula. For individuals with short-arm posterior canal BPPV, nystagmus may not reverse when individuals return to a seated position
